title: Biodegradable and injectable paclitaxel-loaded poly(ester amide)s microspheres: fabrication and characterization.
abstract: Novel biodegradable submicron microspheres of amino acid based poly(ester amide)s (PEAs) were fabricated by an oil-in-water (O/W) emulsion/solvent evaporation technique and their morphology and drug loading efficiency were examined. PEAs microspheres of mean diameter <1 microm with very narrow size distribution were obtained at a fair yield about 80%. The effects of PEA polymer concentration, polyvinyl alcohol emulsifier concentration, and the homogenizer speed on the size and morphology of final PEA microspheres were examined by analyzing their SEM images. It is found that a low PEA concentration, a high PVA concentration, and a high homogenizer speed are the optimal conditions for obtaining smaller microspheres. The biodegradation behaviors of these PEA microspheres at 37 degrees C were investigated as a function of enzyme (alpha-chymotrypsin) concentration and incubation time. The data showed similar surface erosion degradation mechanism as PEA polymers reported previously. Paclitaxel loaded PEA microspheres with high encapsulation efficiency were obtained without significantly affecting their size and surface morphology. The high drug loading efficiency close to 100% suggested that PEA microspheres may have the potential for the injection administration of highly hydrophobic anticancer drugs.
authors.affiliation: Fiber and Polymer Science Program, Department of Fiber Science and Apparel Design, and Biomedical Engineering Program, Cornell University, Ithaca, New York 14853-4401.
authors.forename: Kai
authors.initials: K
authors.lastname: Guo
authors.affiliation: Fiber and Polymer Science Program, Department of Fiber Science and Apparel Design, and Biomedical Engineering Program, Cornell University, Ithaca, New York 14853-4401.
authors.forename: C C
authors.initials: CC
authors.lastname: Chu
mesh_terms: D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000008:administration & dosage / Q000737:chemistry; D001672:Biocompatible Materials / Q000737:chemistry / Q000378:metabolism; D004337:Drug Carriers / Q000737:chemistry / Q000378:metabolism; D016503:Drug Delivery Systems; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D015394:Molecular Structure; D008970:Molecular Weight; D009757:Nylons / Q000737:chemistry / Q000378:metabolism; D017239:Paclitaxel / Q000008:administration & dosage / Q000737:chemistry; D010316:Particle Size; D011091:Polyesters / Q000737:chemistry / Q000378:metabolism; D013499:Surface Properties
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D001672:Biocompatible Materials; D004337:Drug Carriers; D009757:Nylons; D011091:Polyesters; D017239:Paclitaxel